Would agree with the above while adding the type of BC that you choose must have sufficient lift for the type of equipment and diving conditions that you'll be diving in. Technical divers, such as CS, require tremendous lift capacity due to the amount of equipment that they take with them to the depths below. However, the diver in the carribean doesn't need as much lift due to the lack of equipment necessities.
So, fit, comfort, amount of lift based on diving equipment and situations. If you may eventually expand your horizons, might I suggest a BCD that will grow with your needs: a modular system such as the X-Tec from Scubapro or the Dive Rite system.